[mmorett]

Since a reply link isn't available for spacemanaki's comment, I'll stick it here:

"The purpose of a question like this, and of the classic FizzBuzz question, is to be a lightweight test of whether a candidate can actually write code or not. That's all. It provides a negative signal if they fall completely to get anywhere close, and nothing more."

I disagree. Vehemently. Provide me an email address and I'll mail you tons of code I've written. You cannot, cannot conclude with any accuracy that the inability to code up a method/function to check an anagram means that the person cannot write code. What you can conclude is that they cannot write up a method/function to check an anagram.

You're making an assumption. If a = b and b = c, then a = c. That works in math class but not here. The test is not one of syntax or knowledge of the language but of knowledge of a specific problem. Some here have used the word "trick". I don't even need to go there. Once you have the answer to this anagram exercise, you can back into why it's a good question, what it supposedly shows, etc. At that point you're justifying the question and defending it.

But you missed the entire point of the exercise: you're supposedly screening candidates for knowledge of a language and how they might have used it in their past experience, but letting it all come down to whether they solve your specific problem on the spot with all of Pamela's concerns about stress, etc.

It's easier to ask about an anagram than to ask about a candidate's past and what they did on their projects. If not an anagram, there are others. There will always be "solve this now" rather than "tell me about..." That's just the game.

[philwelch]

> You cannot, cannot conclude with any accuracy that the inability to code up a method/function to check an anagram means that the person cannot write code. What you can conclude is that they cannot write up a method/function to check an anagram.

If you can't check an anagram given the definition of an anagram and the programming language of your choice, what problems can you solve? It's not a hard question and if you can't come up with a correct solution at all, I dare say you lack the ability to program.

[karlmdavis]

So, I understand and am incredibly sympathetic to the stress problem some folks have. I also occasionally freeze up when put on the spot, though I fortunately tend to recover after a minute or so of verbal stumbling.

That said, hiring quality engineers is HARD, and often ends up coming down to a numbers game. If I've got 100 applicants to go through and know (from past experience) that over 80% of them couldn't code their way out of a wet paper bag, then I need short, deterministic interview techniques that will identify those candidates who are actually worth my time. Thus: fizzbuzz. I've met lots of folks who talk a great game, have all kinds of experience listed on their resume, and yet somehow can't write up a linked list or fizzbuzz solution in any language.

So, I accept that there will be some false negatives in order to more quickly narrow the focus down to those few rare folks that can actually code. It sucks: it isn't entirely fair to folks who struggle with stress/nerves, but I need a 5-15 minute litmus test that can be done remotely and I haven't found anything else more effective.

Short of wasting everyone's time with take-home projects (which I often employ in later stages of the interview process), what other options are out there?

[mmorett]

That's the $64,000 question. If I knew the answer, that would be my startup. It's a tough problem. It almost makes one beg for some sort of one-off certification (bar exam?) so we can put that to rest for ever after. I'll go out on a limb and say that most lawyers, especially the senior ones, probably couldn't pass the bar exam again. Developers have a mini bar exam every time they interview (hence the studying).

That said, there's one thing you wrote I took interest in: "I've met lots of folks who talk a great game, have all kinds of experience listed on their resume, and yet somehow can't write up a linked list..."

Umm...that would be me. I've never written a linked list. Guilty as charged. Java has a LinkedList class and I've never bothered to look at the implementation nor have I ever been curious enough to (re)write one from scratch.

I wish you would have said "...and yet somehow don't know when to use a linked list." That moves it from an academic exercise mostly applicable to CS students who might have written one 6 months ago, to a meaningful real world scenario and more than legitimate. Choosing the appropriate data structure, knowing when and why, is both realistic and important. I don't know how a candidate can bullshit their way thru a discussion of data structures where they can articulate, accurately, which one to use, when, and why.

[karlmdavis]

> I've never written a linked list. Guilty as charged. Java has a LinkedList class and I've never bothered to look at the implementation nor have I ever been curious enough to (re)write one from scratch.

Good! You're right: the JDK's implementation is perfectly acceptable, and you'd be crazy to write your own. I certainly haven't, either.

But if you have any CS education, I'll bet you know what a linked list is at a high level. And I can probably verbally walk you through turning that into a "spec" that's good enough for a basic whiteboard implementation of one that supports a couple of basic operations. It's (hopefully) just another fizzbuzz: a simple problem to demonstrate that you can code something/anything. The overwhelming majority of applicants can't.

[dkersten]

I'll ask you a slightly different question then: when is it appropriate to use a linked list? In which of those cases might it still be inappropriate and why?

These things can be memorized of course but I find that if one has a reasonable understanding of the underlying machine and knows how to implement a range of data structures and algorithms the answer to these questions (for most of the less specialized data structures) becomes quite straightforward. Whether that is relevant very much depends on the job being interviewed for however.

[jebblue]

Salient points all, I wish I could have stated my views as eloquently.